Need diagnosis help for Barely Running

[otis]

Hi All,

My truck has always run great, recently it started running rough during start from stop, Then was fine at stable speed. No OBD 1 codes, But I changed the inline fuel filter as a guess. This weekend it barely idled and I was getting 33 & 44 codes. I swapped the MAP sensor last night and it was immediately fine, with no codes. Today, Drove to the store fine, Coming home, The shaking/shuddering is back at all times(idleing/driving), Still no OBD 1 codes.

Plugs, cap, rotor, wires are new, O2 sensor is 40K old, EGR 20K old; I'm thinking fuel pump, TP sensor, crank sensor, Plugged Cat (It rattles/has for 30K)

Thanks for any help - Otis

 

95 GMC Yukon, 145 K

5.7L gasoline, 4 door, 2 wheel drive, single exhaust

[SoCalChris]

Sounds similar to what our 99 Safari was doing. It was the crankshaft position sensor. The dealer replaced it for under $200.

[Matt99Z71]

sounds like a egr, does it do it at wot?